const obj = {
  a: 1
}

//obj.a
// obj.toString()
//V8查找规则



Car.prototype.run = 'running'
function Car() {
  this.name = 'su7'
  this.height = 1400
  // var this = {
  //   name: 'su7',
  //   height: 1400
  // }
  // this.__proto__ = Car.prototype
  // return this
}
let car = new Car()
console.log(car);
